Use your Noodle

I was mounting the 60oz Dubro fuel tank in the Reaction 54 and noticed I didn't have much foam padding on hand to do the job
Then found the foamy-pool-Noodle in the basement. Heck cut into 1/2 slices it worked great - Glued into place with spray 77 glue
the fuel tank now fits like a tight glove and firmly locked into the model with 2 balsa cross members.

I made multiple identical 1/2 slices by rapping the Winnie with 1/2 wide masking tape to guide my razor saw.